[Studies on the various sugar-urea and sugar-starch-urea relationships with reference to the fermentation in the rumen and the digestibility of nutrients in fattening cattle]. / Untersuchung des unterschiedlichen Zucker-Harnstoff- und Zucker-Stärke-Harnstoff-Verhältnisses im Hinblick auf die Fermentation im Pansen und auf die Verdaulichkeit der Nährstoffe beim Mastrind

Recommendations are given saying that sugar-to-crude fibre rations of not more than 1.7:1 and sugar-to-urea ratios of 12:1 should be used in the fattening of cattle fed urea-supplemented rations of roughages in which 40% to 50% of the crude protein content of the ration had been replaced by urea. The amount of sugar per kg live-weight should not exceed 4 g. Higher quantities reduce the digestibility of crude fibre and, additionally, decrease the NH3 level and the pH in the rumen. At the same time the amount of volatile fatty acids is increased while the content of ruminal acetic acid decreases. Variations in the sugar-to-starch ratio had no statistically significant influence on the nitrogen balance whereas it was found that increasing quantities of sugar significantly decreased the digestibility of crude fibre. The proportional content of sugar in the readily metabolisable carbohydrates contained in the ration should not exceed 20% to 50%.